1. Field of the invention
The present invention refers to a container functioning as a product dispenser, generally for cosmetic or pharmaceutical type products under solidified fluid stick form, such as deodorants or lip-sticks, or for viscous fluids, such as creams, gels and the like.
The container is of the type which includes a propelling carrier with a central threaded aperture, functioning as a stick holder cup or a pressing piston having a rotational and sliding movement controlled by an axial screw threaded shaft, following a relative rotation of two outer bodies of the container which are rotatable one to other.
2. Description of the Prior Art
Containers of this general type are already known from prior art, examples of which are containers for lipsticks and stick-deodorants present on the market, and those described in the published European patent application No. 0332593, also including cream dispensers.
The container dispensers described in the above patent applications, comprise a tubular outer case with a circular cross sectional internal surface, open on its upper part and closed at its base, and a screw threaded shaft rigidly connected to the closed base, projecting along the axis of the case, a tubular inner sheath, coaxial to the outer case, with a lower part having a rotatable cylindrical outer surface in sliding contact with the inner surface of the case and a closed base provided with a hole, and an upper part projecting above the case, a movable carrier threadedly engaged with the screw shaft through the central aperture, and having a transversal diaphram and an outer wall in sliding contact with the inner surface of the inner sheath, forming an elastic friction sealing, engagement means on the sheath and on the case suitable for preventing a relative movement in the axial direction of the sheath and the case, so that these may achieve only a relative rotational movement around their common longitudinal axis, and a cap.
The process of moulding the shaft in a single piece with the base of the outer case can be difficult, the shaft being moulded inside a beaker-shaped case, and provided with a series of undercuts resulting from the reduced pitch thread.
In the above mentioned Italian patent application 47736A89 there have been illustrated shafts provided with a basal platform, moulded separately from the bottom of the case and subsequently made integral by engagement between surfaces which extend in an axial direction.
One must take into account that the ease of moulding of such bodies which make up the container is of fundamental practical and commercial importance.
Other conventional containers present on the market for stick products contain a carrier or cup screwed onto a shaft integral with the outer case and sliding along the inside of the inner sheath. The carrier is normally provided with one or more guiding grooves on its outer surface which engage with respective guiding splines on the inner surface of the inner sheath, in a way to be forced to move in an axial direction, to avoid that the rotation of the outer case drags it in joint rotation.
The presence of splines is often prejudicial to the external appearance of the stick product.